1. Technical Field
The present invention relates in general to the field of electronic apparatuses. More particularly, the present invention relates to the field of cooling electronic apparatuses. Still more particularly, the present invention relates to a system of cooling interior and external housing surfaces in electronic apparatuses.
2. Description of Related Art
Recently, for compact electronic apparatuses such as portable personal computers (PCs), the performance of internally provided electronic components has been improved and their installation density has been increased. As a result, during the operation of the compact electronic apparatuses, heat generated by the internally mounted electronic components has become a serious problem. Since there is a tendency that the thickness, weight, and size of the housings are reduced, the heat generated by the electronic components tends to be retained internally. Therefore, to ensure the performance and the reliability of electronic components, there is a need for a system of removing generated heat quickly to cool the housings of a data processing system such as a PC.
Since housings provided for compact electronic apparatuses have gotten smaller as the demand for more compact data processing systems increase, the installation of cooling apparatuses in the housings, such as fans, is difficult. Therefore, parts such as copper plates, aluminum plates, or heat pipes have been employed to move heat from heat generating sources to locations where the heat can be discharged. If the generated heat is not removed, the performance of the electronic components within the data processing system will degrade.                According to one method for locating a fan inside a housing, a very small fan with a limited flow rate is employed. Since the density in which components is high, it is difficult for air impelled by the fan to be dispersed throughout the housing. This difficulty results in electronic components within the data processing system that do receive adequate cooling. When electronic components are inadequately cooled, erroneous operations or failures may occur, and the safely and reliability of the components may be degraded.        
According to another method for transferring head generated by an electronic component, heat is conveyed to the inner surface of a housing and is externally removed at its outer surface. Since the removal of heat from the outer surface of the housing depends on the natural transfer of heat based on the difference between atmospheric temperature and the surface temperature of the housing, the heat discharge effect is not satisfactory. Furthermore, since during operation, the temperature at the surface of the housing is high, a person who comes in contact with the surface will experience an uncomfortably hot sensation which may result in a burn if the contact with the housing surface continues for an extended period of time. Thus, since people tend to carry personal computers, such as mobile PCs, in their hands or use them in their laps, heat at the surfaces of the housings has also become a problem. From the viewpoint of the users, measures are required (e.g., temperature reductions and surface cooling) that will reduce the heat of housing surfaces that regularly come in contact with the user. As a conventional countermeasure, the surfaces of housings are covered with materials with low thermal conductivity, such as resin. According to this method, only a small amount of heat is removed from the housing surfaces, and only reduced cooling effects are provided for internal electronic components.
Conventional techniques for the provision of cooling apparatuses in portable PCs are also disclosed in Japanese Utility Models No. 3064584 and No. 3043379, for example. However, these techniques are provided merely for the cooling PC housing interiors, not for reducing the temperatures of housing surfaces.